Turkish Journal of Medical Sciences Turk J Med Sci (2016) 46: 756-763 http://journals.tubitak.gov.tr/medical/ © TÜBİTAK Research Article doi:10.3906/sag-1502-110 Sevoflurane versus propofol for electroconvulsive therapy: effects on seizure parameters, anesthesia recovery, and the bispectral index 1 2, 2 3 Melekşah PEKEL , Nadide Aysun POSTACI *, İsmail AYTAÇ , Derya KARASU , 4 5 6 7 Hüseyin KELEŞ , Özlem ŞEN , Bayazit DİKMEN , Erol GÖKA 1 Department of Anesthesiology and Reanimation, Private Deniz Hospital, İzmir, Turkey 2 Department of Anesthesiology and Reanimation, Ankara Numune Education and Research Hospital, Ankara, Turkey 3 Department of Anesthesiology and Reanimation, Bursa Şevket Yılmaz Education and Research Hospital, Bursa, Turkey 4 İstanbul Forensic Medicine Institute Sixth Forensic Medicine Council, İstanbul, Turkey 5 Department of Anesthesiology and Reanimation, Doktor Abdurrahman Yurtaslan Ankara Oncology Education and Research Hospital, Ankara, Turkey 6 Department of Anesthesiology and Reanimation, Faculty of Medicine, Gazi University Ankara, Turkey 7 Department of Psychiatry, Ankara Numune Education and Research Hospital, Ankara, Turkey Received: 19.02.2015 Accepted/Published Online: 30.07.2015 Final Version: 19.04.2016 Background/aim: In this prospective randomized cross-over study we compare the effects of sevoflurane versus propofol for electroconvulsive therapy (ECT) anesthesia. Materials and methods: Twenty four patients (ASA I–III, 18–65 years old) receiving ECT three times per week were included. Anesthesia was induced with either propofol (0.75 mg/kg iv) or 5% sevoflurane in 100% oxygen. Consecutive ECT sessions followed a 2 × 2 crossover design and a 2-day washout period until the 10th ECT. Intravenous succinylcholine (1 mg/kg) was administered while bispectral index (BIS) values were ≤60%. Results: Electromyogram and electroencephalogram seizure duration, postictal suppression index, BIS values, mean arterial blood pressure (MAP), heart rate, times to start of spontaneous respiration, eye opening, understanding verbal commands, and side effects were compared. No differences were found between the regimens for seizure activity and recovery. At the end of ECT, MAP was higher with sevoflurane. Although BIS values were higher after sevoflurane, no differences between the regimens were found in terms of the need of muscle relaxants and in hypnosis levels. Conclusion: Sevoflurane (5%) may be an effective alternative to propofol for induction of anesthesia for ECT. Key words: Electroconvulsive therapy, anesthesia, propofol, sevoflurane, bispectral index 1. Introduction degree of EEG flattening at the end of seizure and indicates Electroconvulsive therapy (ECT) is the preferred treatment ECT seizure quality. The PSI is also reported to correlate for affective disorders, and especially major depression, with clinical efficacy (3,5,6). schizophrenia, and other psychotic disorders that do Agents used to induce anesthesia for ECT should not respond well to psychopharmacological treatment, provide rapid induction and recovery, have few side effects, when pharmacologic treatment is not well tolerated or and not reduce the effectiveness of ECT. However, no in situations when a fast clinical response is required. anesthetic agent is known to provide all these requirements. Despite disagreements on the relationship between the A sensitive balance is required between providing optimal effectiveness of ECT treatment and seizure duration, the seizure duration and achieving a sufficient depth of suggested time for clinical effectiveness is 25–30 s (1,2). anesthesia (1). Whereas high-dose anesthetic agents might Moreover, electroencephalogram (EEG) signs of intense reduce the effectiveness of ECT, low-dose agents may not seizure with high amplitude and postictal EEG suppression provide an adequate depth of anesthesia and may also are reported to be indicative of the efficacy of treatment negatively affect the progress of the psychiatric disease (1–5). The postictal suppression index (PSI) reports on the (7,8). Direct measurement of the individual hypnosis level * Correspondence: [email protected] 756 PEKEL et al. / Turk J Med Sci is reported to help in determining the anesthetic dosage 2.2. Study design and ECT application time, as well as reducing awareness Patients were randomized (using the sealed envelope (9,10). The bispectral index (BIS) is an EEG-derived scale method) to either IV propofol (0.75 mg/kg) or sevoflurane reflecting the level of hypnosis and an important parameter (5%). This study was performed using a 2 × 2 crossover in anesthesia for ECT (9–11). design with a 2-day washout period until the 8th ECT Inhalational induction for ECT is preferred for patients session, at which point the study ended. Electrical with needle phobia, agitation, (known) problems related stimulus trigger points were determined during the first to inserting an intravenous (IV) line, and for patients with two ECT sessions; these two sessions were not included in (expected) difficult airway management (12). Sevoflurane the present analysis, and in these sessions propofol and IV is an inhalation anesthetic that provides fast and smooth remifentanil were used for induction of anesthesia. induction, has a quick elimination, and does not irritate 2.3. Procedure and data collection the airways (13). It is also preferred in the last trimester of Patients were brought to the ECT room without any pregnancy for ECT anesthesia because it reduces uterine premedication and were administered Ringer’s lactate contractions (14). Although studies have compared infusion after insertion of an IV line in their forearm. induction with sevoflurane and IV anesthetic agents, there Electrocardiogram (ECG), noninvasive blood pressure, is no consensus on the effects of sevoflurane on seizure heart rate (HR), peripheral oxygen saturation (SpO2), end- duration (12,15–18). It is emphasized that the depth of tidal carbon dioxide (Datex Ohmeda S/5, Bromma), and anesthesia should be determined during induction of BIS (BIS XP, Aspect Medical System) were monitored. anesthesia for ECT (18,19). Hemodynamic data were recorded before induction, after In the present study the level of hypnosis was monitored induction, immediately at the end of ECT (ECT-E), and using BIS. The aim was to compare hemodynamic at 1 and 5 min after the end of ECT (ECT + 1 and ECT responses, BIS scores, seizure parameters, and recovery + 5, respectively). BIS values were recorded before and profiles for sevoflurane and propofol for induction of after induction, before administration of muscle relaxants, anesthesia for ECT. immediately before ECT (preictal) and 5 min following ECT (postictal). 2. Materials and methods ECT was applied bilaterally using the Thymatron TM DGx device (Somatics LLC). EEG electrodes were 2.1. Overview placed on the frontal and mastoid protuberances by the This single-center, single blind, randomized, prospective, psychiatrist and the electromyogram (EMG) electrodes crossover exploratory study was performed at Numune were placed on the flexor side of the right forearm. Seizure Educational and Research Hospital (Ankara). The study quality was determined using the PSI, which is calculated was approved by the local Institutional Ethics Committee by the Thymatron device. All patients were preoxygenated (2007-08884). with 4 L/min 100% O2 for 3 min using a face mask; A total of 27 patients (aged between 18 and 65 years) additionally, 1 min before induction IV remifentanil receiving ECT three times a week (to complete an average 1 µg/kg was administered over 30–45 s (in our clinic of 10–12 treatments) were enrolled in the study (between remifentanil is used routinely to reduce the dosage of the 2007 and 2009). Patients with mask phobia, epilepsy, induction agent and to suppress hemodynamic response). unstable cardiovascular disease, sinus bradycardia, second For the first treatment, patients received ECT at 30%– or third degree atrioventricular block, cerebrovascular 50% of the maximum output stimulus, depending on disease, chronic obstructive pulmonary disease, hepatic the attending psychiatrist’s decision. After the first ECT or renal insufficiency, organic brain disease, current session, the same psychiatrist decided on the stimulus alcohol use or other substance dependence, and patients amplitudes according to the patient’s clinical outcome. receiving treatment with beta blockers, anticonvulsants, or In the propofol regimen, propofol 0.75 mg/kg was benzodiazepines were excluded from the study. administered IV over After the patients (or their relatives) were informed 30–45 s. Patients were clinically assessed approximately about the study and signed consent forms, patients were 60 s after propofol administration and additional propofol examined and classified as ASA physical status I–III prior was given in 10–20 mg increments as needed until loss of to ECT treatment. During the study, the following patients eyelash reflex and loss of response to verbal commands. were also excluded from the analysis: patients who could The total propofol dosage was recorded. no longer tolerate mask induction, those who had a very In the sevoflurane regimen, the respiratory circuit was high level of trigger points, patients who had a seizure primed for 60 s using sevoflurane 5% in 100% O2 with a duration ≥120 s, and patients whose treatments were 4 L/min gas flow. Patients were asked to breathe through completed earlier than planned (<8 ECT sessions). the face mask connected to